Brexit: Michel Barnier says Britain can REJOIN the European Union

"The door is open, any time, I always say that during negotiation, after negotiation, the door remains open," he told ITV.

"But to be clear, the UK government, the current Government, the next Government, knows exactly what are the terms and conditions to be part of the single market, to be part of the customs union, to rejoin the EU.

"The point is to know exactly what would happen during this time.

“What would be the size of divergence between us and a new candidate."

Barnier also slammed former Prime Minister Boris Johnson, who campaigned with Vote Leave in 2016 and pledged to ‘Get Brexit Done’ just three years later, for allegedly not respecting deals he signed during UK-EU negotiations.

He said: "We signed with him not only the treaty on trade but the previous one, the first Brexit constitution, the divorce, including the [Northern] Irish Protocol.

He said: "We signed with him not only the treaty on trade but the previous one, the first Brexit constitution, the divorce, including the [Northern] Irish Protocol.

"So the point is not to sign a treaty, the point is to respect the treaty and to respect its own signature and I never understood, I do not still understand, how the Prime Minister of such a country, a great country like the UK, can be able not to respect his own signature.”

The United Kingdom voted to leave the European Union in 2016, with 17.4 million ballots cast to leave the bloc and 16.1 million backing continued membership.

The Conservative Party doubled down on its Eurosceptic mandate in 2019 when it was elected to a thumping 80-seat majority.

However, recent opinion polls suggest the tide is turning against Brexiteers.

An Omnisis survey conducted earlier this month found 49 per cent of voters would support rejoining the EU and just 31 per cent wish to stay out.

Nearly two-thirds of voters believe Brexit has contributed to runaway inflation and soaring food prices amid the ongoing cost-of-living crisis.

Former Bank of England policy maker Adam Posen blamed Britain’s departure from the Brussels bloc for most of the UK’s inflation issues.

Experts at the London School of Economics suggest support for rejoining the EU is not a foregone conclusion as economic recovery, talk of the Euro and a cross-continent debt package could diminish Britain’s newfound Europhilia.

The continent is also struggling to grapple with ever-increasing costs.

The UK avoided a recession with 0.1 per cent growth in the first quarter of 2023 but the Eurozone suffered two consecutive slumps.

Germany tipped into recession this year after growth contracted by 0.3 per cent.

The Republic of Ireland was the worst-performing economy in the 27-nation bloc as first quarter output collapsed by 4.6 per cent at the start of the year.

The Conservative Party, led by Brexit-backer Rishi Sunak, remains committed to securing a bright future outside the EU.

Sunak said: “I voted for Brexit, I believe in Brexit. As Chancellor and Prime Minister, I am actually delivering the benefits of Brexit as opposed to talking about it."

Labour leader Sir Keir Starmer, who faces some challenges from MPs and critics on the left, is committed to securing a "better Brexit deal" but does not want another referendum on EU membership.

The ex-Shadow Brexit Secretary has also pledged not to drag the UK back into the EU's single market or customs union.

The Liberal Democrats hope to rebuild cross-Channel ties on education, asylum seekers and trade, with the eventual aim of seeking to rejoin the single market.